I have been looking at different geometries for solids in the application for developers. However, I’m having trouble finding the correct solid to construct something similar as in the attached scetch (side view). To clarify, it is almost a cone solid, except that the surface area has a parabollic shape instead of linear.
Indeed, there is no such solid. You can approximate it either by G4TessellatedSolid or by sequence of G4Cons.